The present invention is generally directed to computer controlled manufacturing systems, and more particularly to control of application programs in a multi-tiered computing arrangement.
Early computer controlled manufacturing arrangements, for example, those for manufacturing semiconductors, generally included a central computer system for controlling the overall factory floor. Coupled to the central computer system, via a network for example, were satellite computers programmed for respectively controlling selected tools. The tools were often directly coupled to serial or parallel ports or special adapter cards of the satellite computers.
The early systems generally controlled a single tool with a single satellite computer. Thus, a single process running on the single computer provided communication between the central computer system and the single tool. As manufacturing output requirements increased, additional tools were coupled to the satellite computers. To establish the required communications between the central computer system and the newly added tools without incurring undesirable delays associated with developing new software, replicated processes were used. Specifically, for each tool coupled to a satellite computer, a respective process executing on the satellite computer provided the necessary communication interface between the central computer system and the tool.
The total commuter and human resources consumed by adding new processes each time new tools are coupled to satellite computers has become significant. Generally, the resource requirements are some function of the number of satellite computers and the number of tools. Thus, in a large manufacturing arrangement, the resource requirements can be considerable. Therefore, a system and method that addresses the above identified problems is desirable.
In one embodiment, a method is provided for inter-tier application control in a multi-tier computing environment that includes a first tier application program, a second tier application program, and a plurality of third tier control elements, wherein the second tier application program initiates processing of the third tier control element in response to messages from the first tier application program. The method comprises associating connection identifiers that respectively reference connections between the second tier application program and the third tier control elements with respective third tier control element identifiers. For messages that are sent from the first tier application program to the second tier application program to initiate processing sequences by the third tier control elements, respective third tier control element identifiers are indicated for the messages, The second tier application program performs application specific processing on the messages, and connections are selected for transmitting control messages to the third tier control elements based on the indicated third tier control element identifiers and the associated connection identifiers.
In another embodiment, a method comprises associating connection identifiers that respectively reference connections between the second tier application program and the third tier control elements with respective third tier control element identifiers and receiving a message from the first tier application program. A third tier control element identifier based on the message is indicated to the second tier application program, and the second tier application generates a control message. The control message is transmitted to a third tier control element via a selected connection that is based on the indicated third tier control element identifier and associated connection identifier.
An apparatus is provided for inter-tier application control in a multi-tier computing environment that includes a first tier application program, a second tier application program, and a plurality of third tier control elements, wherein the second tier application program initiates processing of the third tier control element in response to messages from the first tier application program. The apparatus comprises means for receiving messages from the first tier application by the second tier application; means for mapping messages received from the first tier application to respective connections between the second tier application and the third tier control elements) and means for transmitting control messages generated from the received messages to the third tier control elements via the respectively mapped connections.
In another embodiment, a multi-tier computing arrangement is provided that comprises: a first tier computer system arranged to host a first tier application program; a plurality of third tier control elements; and a second tier computer system coupled to the first tier computer system and to the third tier control elements and arranged to host a second tier application program. The second tier application program includes: a first connection layer arranged to receive messages from the first tier application program; a first mapping layer arranged to indicate to the second tier application program a third tier control element identifier based on the message and associate connection identifiers that respectively reference connections between the second tier application program and the third tier control elements with respective third tier control element identifiers; a core logic layer arranged to generate a control message; a second is mapping layer arranged to select a connection to a third tier control element based on the indicated third tier control element identifier and associated connection identifier; and a second connection layer arranged to transmit the control message via the selected connections.
The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description which follow more particularly exemplify these embodiments.